Cathodic protection (CP) is an established corrosion control technique that prevents corrosion of metallic structures exposed to corrosive environments like soil, seawater, or concrete, ensuring long-term asset integrity.
At Corrpro Europe, we draw on over 50 years of expertise to deliver reliable, engineered CP solutions tailored for infrastructure across industries including oil and gas, marine, energy, and construction.
Understanding Corrosion and the Role of CP
Corrosion occurs when some metals are exposed to their environment, causing some areas to become anodic and others cathodic. This allows electric current to flow between these locations, resulting in metal loss at the anodic locations. If left to continue, this process compromises structural integrity. Cathodic protection prevents corrosion by polarising the entire metal surface to a more negative potential, making it entirely cathodic. By polarising the metal negatively, cathodic protection suppresses the oxidation reactions responsible for metal loss. This can be achieved either by connecting a galvanic (sacrificial) anode with a more negative potential to the metal or by applying an impressed current through inert. For Cathodic Protection to function an anode, a cathode, a conductive electrolyte and a connection between the anode and cathode is required.
Types of Cathodic Protection Systems
Corrpro Europe designs and supplies the two principal types of CP systems, each suited to specific project needs and environments.
Galvanic (Sacrificial) Anode Systems use metal alloys, typically zinc, magnesium, or aluminium as sacrificial anodes. These anodes have a lower electrochemical potential than the structure intended to be protected and corrode instead of the structure. Galvanic anode systems are self-regulating and are ideal for smaller or well-coated structures, such as short lengths of underground pipelines, tanks internal and external surfaces, and marine structures.
Impressed Current Cathodic Protection (ICCP) Systems utilise an external DC power source to deliver protective current using inert anodes such as mixed metal oxide (MMO) or high-silicon cast iron. These systems are well suited for larger structures or applications, with higher current requirement, such as cross-country pipelines, industrial plants and offshore structures. Corrpro Europe’s Hockway™ transformer rectifiers, built in the UK, are integral to these systems, offering high reliability and performance even in hazardous areas.
Applications Across Industries
Corrpro Europe’s CP systems are applied to a diverse range of infrastructure:
- Buried and submerged pipelines
- Buried and above-ground storage tank bases
- Internal surfaces of tanks
- Offshore oil and gas platforms and FPSOs
- Ships, vessels, jetties, piling, and marine terminals
- Solar Farms and BESS systems
- Offshore Wind sites
Cathodic protection works effectively alongside protective coatings to extend service life. As the coating degrades over time, cathodic protection continues to prevent corrosion, ensuring long-term asset integrity.
Components of a Cathodic Protection System
A typical CP installation includes:
- Anodes, either galvanic or impressed current, which deliver protective current.
- DC power sources such as transformer rectifiers for ICCP systems, providing controlled DC output.
- Cables and connections, designed to withstand harsh conditions and maintain electrical integrity.
- Reference electrodes, coupons, ER Probes and test stations, which allow for ongoing monitoring and verification of CP effectiveness and AC / DC interference levels.
Corrpro Europe manufactures and supplies these components in-house, maintaining high quality control and offering short lead times.
Benefits of Implementing Cathodic Protection
Cathodic protection offers tangible long-term benefits:
- Extended Asset Life: CP significantly reduces corrosion-related degradation.
- Cost Efficiency: Investment in CP mitigates expensive repairs and environmental liabilities.
- Safety and Compliance: CP systems support compliance to international and national regulations, industry standards, including ISO 15589-1 and ISO 15589-2 and NACE SP0169.
- Adaptability: CP can be retrofitted to existing infrastructure, extending life and preserving asset value.
Corrpro Europe’s Expertise and Capabilities
Corrpro Europe stands apart by offering full-spectrum cathodic protection services and materials:
- Engineering Services: Our ISO (ICorr) and NACE-certificated engineers provide site surveys, CP designs for complex requirements, installation support, commissioning and support for operation and maintenance.
- Manufacturing: With UK-based facilities in Stockton-on-Tees, we produce high quality aluminium, magnesium, zinc, and MMO anodes, cables, junction boxes, and transformer rectifiers.
- Marine Systems: Our Aquamatic® ICCP and Aloline®/Zincoline® sacrificial anode solutions protect vessels and offshore structures.
- Remote Monitoring and Control, Data management: The CorrMonitor platform offers real-time system status, enabling predictive maintenance.
Our remote monitoring and control equipment for cathodic protection systems, enables real-time measurement of corrosion rates and system performance. Our engineers analyse data to assess system condition and efficacy, troubleshoot issues, manage data, generate value-added engineering reports, and monitor AC/DC stray current interference.
Monitoring and Maintaining CP Systems
Effective cathodic protection depends on regular monitoring and maintenance. Corrpro Europe offers comprehensive lifecycle support:
- Potential Surveys: Including Close Interval Potential Surveys (CIPS) to identify under-protected zones.
- Anode Assessment: Inspection of anodes to determine remnant lifetime and performance.
- System Balancing: DC power units may require output adjustment as environmental or operational conditions change.
- Remote Oversight: Our systems provide continuous data acquisition and alerts, enabling real-time monitoring of cathodic protection performance. In addition, our engineers conduct monthly expert analysis and provide recommendations to support proactive system management.
Cathodic protection is essential for the long-term and extended life performance of critical infrastructure. Corrpro Europe offers competently engineered standards-compliant CP systems combining decades of experience with UK manufacturing excellence. Whether designing for new construction or retrofitting existing assets, our team delivers dependable, technically robust CP solutions to the most complex of requirements.
To explore how Corrpro Europe can support your next project, contact our team.
FAQs
What does cathodic protection actually do?
Cathodic protection prevents corrosion by polarising the metal structure, shifting its electrochemical potential into a range where corrosion reactions are minimised. This is achieved by turning the structure into a cathode, using either sacrificial anodes or impressed current systems to supply sufficient electrons to prevent metal loss.
Where is cathodic protection used?
CP can be applied anywhere metal is in direct contact with soil, water, or seawater , even concrete and at risk of corrosion. Common examples include pipelines, underground storage tanks, oil & gas well casings, ship and boat hulls, offshore oil platforms, piling, piers, and water treatment tanks.
What’s the difference between galvanic sacrificial anodes and impressed current?
Galvanic anode systems use more reactive metal alloys like zinc, aluminium, or magnesium that corrode instead of the metallic structure needed to be protected – these systems do not need an external power source. Impressed current systems use a power supply to drive current from specially manufactured typically inert long-life anodes. Galvanic anode systems can be simpler and best for smaller or well-coated structures that require relatively small amount of currents; impressed current systems suit larger structures requiring much greater currents and allows greater adjustment and control of protection levels. (See Article 2 for an in-depth comparison.)
How long do cathodic protection systems last?
A CP system can last for as long as it is maintained. Galvanic anodes do have a finite life – typically between 5 to 20+ years depending on their size and the current demand – after which they need replacement. Impressed current systems can protect indefinitely, but generally longer than galvanic anode systems. ICCP anodes can last more than 20–30 years, if properly designed, manufactured, supplied and operated, and DC power units can last decades but may require occasional component replacements. Regular maintenance ensures the CP system keeps working effectively.
Do I still need coatings or other corrosion measures if I have CP?
Generally, yes, coatings and CP complement each other. A good coating reduces the current demand on a CP system by limiting exposure of metal to the environment, and CP takes care of any coating degradation or inevitable flaws. Together, they offer robust protection. It’s rarely either/or – most pipelines and tanks are coated and cathodically protected. In highly critical systems, CP may also be combined with corrosion inhibitors or other methods as part of a multi-layered defence. Having said this, CP can be successfully applied to bare structures if designed correctly.
